Eight patients with primary malignant pineal tumors have been seen at this institution over the past 6 years; six of them underwent definitive surgical exploration. Complete gross microsurgical excision of well encapsulated tumors was possible in four of these patients. In two cases of pineal germinomas, a biopsy and a subtotal resection were carried out because of the known radiosensitivity of this tumor. These six surgical patients all received postoperative craniospinal radiation and continue to do well up to 6 years postoperatively. Two nonoperative patients were initially treated at other institutions by ventriculoperitoneal shunt and radiation and were the only ones to develop metastatic disease. One patient had metastasis of her pineoblastoma to her unirradiated spinal canal and the other patient had metastasis of his germinoma to the peritoneum. The former patient was quadriplegic on admission, although her pineal tumor was no longer visible on computerized tomography (CT), and she died of pneumonia. The latter patient's tumor secreted the beta chain of human chorionic gonadotropin (HCG). This patient's massive metastatic tumor burden completely regressed as determined by body CT scan and HCG levels after four courses of chemotherapy with bleomycin, vinblastine, and cis-platinum. In 20 patients with lesions of the pineal region, craniotomy was associated with only one death (a patient with metastatic adenocarcinoma). Thus, microsurgery for pineal tumors provides either a reasonably safe potential for complete tumor extirpation and possible cure, or a tissue diagnosis which is necessary for appropriate therapeutic planning for radiotherapy and/or chemotherapy. The traditional therapeutic approach of empiric radiotherapy without a tissue diagnosis for pineal lesions may no longer be warranted.